Fiio X7 AMP Module The AM2 is a replaceable/upgraded amplifier unit that you can use to change the sound quality of your FiiO X7 and is suitable for use with both earbuds and portable headphones. The output power of AM2 is similar to that of most high-resolution music players on the market (such as FiiO X3 and X5). Compared to the FiiO AM1, the AM2 module has a higher operating voltage. Utilizing the MUSES02 by MUSES - the audiophile semiconductor division of New Japan Radio Co. Ltd - for voltage amplification, in combination with the BUF634 buffer - capable of ultra-high current drive (250mA), achieving ultra-low noise and distortion, high resolution and fine sonic detail retrieval. Separate positive and negative pole power supplies are provided, with two-level voltage regulation function corresponding to high and low gain modes, effectively reducing power consumption and increasing playtime. Replacing the modules is extremely easy; simply using the Screwdriver that came with your X7, is merely a matter of undoing 2 screws to remove the AM1 and replace it with the AM2. *Although protection circuits are installed on the X7, it is still recommended to perform the module exchange when the X7 is turned off.* The FiiO AM2 unit comes in a metal protective box which will protect whichever amp you choose to store in there.